Circuit-controlling device.



NO. 802,697. PATENTED OCT. 24, 41905. H. T. HNSN. CIRCUIT GONTRLLING DEVICE.

APPLICATION ILED A.PB.. 2,1904.

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T. J @HN SON F JERSEY y (llrlY, Nil) W .l Eli-SEX.-

ClWCUlTuGNTHULLl NG DlEWlE.

No. shane?.

A "Speciiication of Letters atent.

Patented Oct. 24, 1905.

Application filed April 2, 1904. Serial. No. 201,302.

.To niZZ tchom/ it nfl/nay vcon/cern; 1

' Be it known. that-ll, HARRY' T. JOHNSON, a

.citizen of the United States, and a resident oi' i ing and closing an electric circuit, and is especially adapted for employment in a circuit which includes anV indicator designed to give an alarm when some object 'by which the in- A"dicator is held inoperative is surreptitiously or improperly moved or actuated. As more specifically describingyone field of usefulness for my invention, a burglar-alarm system may be referred to in which an audible or visual alarm is arranged to be given by the movement of some obje'ct-msuch, for instance, as a chair so placed in front of the entrance to a room that it 'I would naturally or inevitably be .moved from such position by any personlsurreptitiously entering -therooing and in order that my invention and its mode ci' operation may be fiillyjbutsuccinctly described I have illus- -tratedan'd will hereinafter describethe same as it is' used., in suchfa burglar-alarm system.

Y ln the drawings,-Figure 1 is a central longitudinalvsection with the vcontacts held apart' by the weight of av chair. Fig. 2 is a plan view. Fig. 3 isa central longitudinal section 4 a modiiication'.

showing thecontacts closed and-also showingv Fig. i is a central longitudinal-'section-showing the parts locked ininoperativeposition with the contacts apart and the .circuit open, andFig. '5 is a plan view thereof. Similar reference .characters are employed y, to designate like parts in all the views.

rlhe particular' form of apparatus embody- -ing'iny invention which l .have illustrated is preferred by me for the particular use to which gli have before referred. lt consists of acylindrical.A shell 1.,. of'conducting metal, provided :with a lange.. `A lug 3 is formed on one i i side ofvv the shell and is apertured to receive 5o` the screw 1i, which serves both as a bindingscrew for one wire 6 of the circuit and also to hold the'device firmly in an aperture formed to receive it in the floor 7. The opposite (or I' when in the position shown the lower) end oi the shell ,l is formed with'an inturned 'tlange 9, upon which rests the insulating and centering `washer 10, which supports the Hanged conducting-bushing 11 and centers it in position out olf-contact with lthe shell 1. The bushing is exteriorly screw-threaded to re- 'ceive the screw-threaded binding-washers 14 and 15, between which is clamped the other wire 16 oi the circuit. An insulating-washer 17 is clamped betweenthewasher l5 and the vend oiI the bushing 9. A plunger 20 is fitted to reciprocate in the shell 1, and in'contact therewith and is provided with a contact-'stem 21, both the plunger and contact-stem being formed of conducting metal. An insulating- "washer 22 rests upon the top of the bushing 11 and supports a washer 23, which serves as an abutment for the'open-coil helical spring 2 which encircles the stem 21 and bears against the under surface of the plunger. The lower end of the stem 21 is split, and the two sections 26 of the ends thu's formed are spread vapart after the plunger is inserted in thevshell, so thalt they will contact with the lower end of the bushing to close the circuit and also to conne the plunger 2O in the shell.

in order to prevent the normaloperation of the'device, l provide a suitable locking means by whichv the parts of the device may be held iixedly'in po ition to prevent the alarm or indicator freniq operating when desired. This, as will be understood by those skilled in the art, may be accomplished in many ways, and

"in the drawings I have shown one simple and ei'ective means i'or accomplishing this, which l will now proceed to describe, but to which it is to be understood my invention is not restricted further. than the limitations in the phraseology oi' the claims may expressly require. The means illustrated comprise a pin or lug1 28 on the inner wall of the shell 1. The

plunger 2O is provided with a longitudinal groove 29, into which the pin 28 projects, the

pin thus furnishing no obstacle to the reciprocation of the plunger. `The groove 29 at its upper end communicates with the horizontal or transverse slot 30, which at its center is deeper than the length of the pin 28, so that when the plunger is depressed, so that its top is substantially iiush with the top of the shell, it may berotated on its axis to cause the pin to enter the transverse slot. When so turned, the pin will hold the plunger and prevent its upward movement and the contacts 26 will be held away from the lower end ci' the bushing 11, as shown in Fig. l. To permit the convenient rotation of the plunger, I provide the top thereof with a slot or depression 31,

IOU

' serted, or the top depressions, so that tated without' the aid of such implement.

30 room is legitimately oceupiedgthc asl shown in 'Fig 3, in which a suitable iniplernent, such as :a screw-driver, may be inroughened by providing it with a number of the plunger may be ro- I- 'l/Vh'en used on an open circuit, the operation oi theform o-dev1ce illustrlated is as follows: rThe device having been properly se- Iq cured in positionas, for instance, in front of adoor or entrance to a roomandthe circuit-Wires having ,been properly connected to ,the terminals, as shown, the plunger is depressed,land one of the legs of a chair 32 or anyother suitable movable object of sutlicient weight'is placed over the device, so that the chair-leg or otherl object will hold the plunger down against the pressure of the spring 24, the ohject'being so placed 4that it will con- 2 ceal the device and will naturally be moved by any person on enteringthe room. llrhen so moved, the plunger being released pressed upwardly by the spring 24.. rlhe conf. tacts'Z will. engage the bottom of the bushing 1l, closing the circuit at that point and plunger is turned in thereverse direction until the pin again enters the groove 29, releasing the plunger.

Havlng thus shown and descrlbed my invention, what Iclaim as new, and desire to secure by Letters Patent, is-

l. In a circuit-controlling device, the combinatlon or' a conducting-shell carrying a lixed of the plunger may hev will he contact insulated therefrom,'means l'or connecting said contact with one wire ol: the cncuit. a spring, a movable Contact held against aegee? said lixed contaethy the-spring and working in contact \vitli"tli.e shell, means for connecting the shell with the other wire of the cir cuit, a pressure-controlled plunger for sepa rating said contacts. and vlocking Ameans for the plunger lor holding the contacts 'apart and rendering the device inoperative when.

the plunger is relieved from pressure.

2. ln a circuit-controlling device, a shell, a

u'essure-controlled 'plunger work-ing therein,

a spring for actuating said plunger to close the circuit-when the plunger is relieved from pressure, and` means for rendering the device inoperative ,by the rotation of the plunger.

'3. ln a circuit-controlling device, the combination of a shell, a plunger working in the shell adapted to be held Awithin the shell by pressure exerted onthe end thereof, a spring for elevating the end of said plunger above the shell when the pressure is removed, contacts adaptedV to be closed when vthe plunger is elevated and means for locking the plunger in the shell against'J the action of the spring to render the device inoperative when such pressure is removed. u

le ln a circuit-controlling device, the conibin'ation ofl a shell and a spring-pressed reciprocating plunger therein,a lugfon one ot' said parts, alongitudinal groove and a transverse slot communicating therewith in the other part to permit the reeiprocation of saidplunger by pressure exerted thereon, and to permit the locking of the plunger movement thereof. y

ln a circuihcentrollng device comprising a shellr and a spring-actuated plunger working therein to open and close the circuit. means i'or locking the plunger in the shell by rotating the plunger and a depression or depressions formed in the top oi' the plunger, for the purposes set forth.

l HARRY '.l`. JOHNSQY. lVitnesses:

C. lninniiurr, i). ll. llorwoon.,

hy a rotational 

